1. Field of Invention
The present invention relates to an operational amplifier. More particularly, the present invention relates to a class AB rail-to-rail operational amplifier.
2. Description of Related Art
For a conventional class AB rail-to-rail operational amplifier (OP), it can be employed to deliver to and pull from a load a current that is larger than the DC quiescent current flowing into the circuit. For example, the drive current outputted from the class AB OP may be 100 milliamps and the quiescent current could be 1 milliamp. However, without limiting the drive current, the drive current could be too large and thus cause the output stage to damage.